With just a couple of weeks to go until her July 11 due date, Kate Middleton took advantage of some downtime to go antique shopping in Hungerford, England, on June 22.Credit: Ikon Pictures

Welcome to the homestretch, Kate Middleton! With just a couple of weeks to go until her July 11 due date, the nearly nine-months-pregnant Duchess of Cambridge is in full maternity leave mode. Since attending her last official engagement with the royal family on June 15, Prince William's wife has kept a very low profile -- but on Saturday, June 22, she stepped out in Hungerford, England, to do a little antique shopping.

With her husband at a pal's wedding -- Middleton, 31, opted the skip the nuptials -- the royal mom-to-be had the afternoon all to herself. She looked relaxed and radiant in black pants, black ballet flats, and a chic trench coat, her long brunette hair pulled into a half-ponytail. As she browsed the wares at Youll's Antiques, she touched a tender hand to her growing baby bump, which peeked out from her open coat.

"Kate looked really happy," an onlooker told Us Weekly of the Duchess, who was accompanied on the outing by a protection officer. "The weather was a bit windy, but she smiled as she walked around the town...Her bump is really big now!"

Added a local: "Kate often goes shopping in Hungerford when she is staying at her parents' house...She has a good eye for British antiques."

Middleton isn't likely to have many solo shopping trips once she gives birth, but she will have several months of maternity leave to bond with her bundle of joy. And in the meantime, she's focused on final preparations.

Credit: Ikon Pictures

As Us Weekly previously reported, the baby's birth will be revealed via a framed announcement placed on a wood and gold easel just behind the gates of Buckingham Palace. (The same wooden easel was last used for William's 1982 birth; the Prince turned 31 on June 21.)

The declaration will be printed, signed by medical staff at St. Mary's Hospital, and then transported (with police escort!) to the Palace, where it will be quickly framed and then displayed. All press releases will go out after the easel reveal.

"Although an electronic release will go out, we want there to be a degree of theatre about the birth announcement," a Palace rep told Us of the pomp and circumstance. "This is the birth of the third in line to the throne so it is very important. It is an extremely important occasion."

"While it is a deeply personal and private event, the Duke and Duchess of Cambridge realize this is a time of national celebration and that there will be vast interest in the baby," another royal aide explained. "They realize many people will want to share in their happiness."